Sphagnum cristatum

Sphagnum Moss

Sphagnum cristatum is the most common species of Sphagnum in
Australia and is the only moss to be used in commercial industry. The Class
Spagnopsida formerly contained a single order, the Sphagnales, with one monogeneric
family, the Sphagnaceae to which S. cristatum belongs. However, the taxonomy
is under current investigation with the recent discovery of a new species, which
possesses significant anomalies relative to the concept of the genus, and as
a consequence, has been segregated into a separate order, family and genus.

Sphagnum peatlands make up only a small percentage of the Australian landscape and are
a unique and distinct environment. They are restricted to the sub alpine zones
of south-eastern New South Wales, Victoria and Australian Capital Territory
and are currently listed as a threatened community.

S. cristatum is a small to robust plant, pale to brownish-green in colour
and forms dense mats of intertwined lateral branches with mop-like heads. It
produces distinct reddish-brown spherical capsules which are borne on a thickened
pseudopodium, but are rarely seen in natural populations, suggesting that reproduction
is chiefly by vegetative means. Spore dispersal occurs in the spring when the
capsules are mature. The leaves of S. cristatum are spirally arranged
and are constructed of an inner core of dead hyaline cells surrounded by a narrow
wall of living photosynthetic cell. The hyaline cells are large and contain
small perforations that allow the plant to absorb and retain almost 20 times
its own weight in water.

Sphagnum moss is used extensively in the horticultural industry because
of its super-absorbent qualities. It is most often used in the propagation of
orchids, as a soil additive to promote water retention and for the long-distant
transportation of rootstock. It has also been used as a surgical dressing since
World War 1 because of its antibacterial qualities and its capacity to absorb
6 times the amount of fluid as cotton.

S. cristatum is not easily cultivated because it requires a very narrow
set of conditions under which it can grow successfully. It needs a stable temperature
of 23-25 degrees, regular watering from a spray system for 20 seconds every
20 minutes and a limited light intensity, so is best suited to glasshouse conditions. Sphagnum doesn't respond well to the chlorine content in tap water and
should only be watered with filtered water. Soil is not required for the cultivation
of Sphagnum - it can be spread thinly into plastic seed trays. Small
amounts of liquid fertiliser can be applied to encourage growth but care must
be taken with the application. Pest control is not needed because Sphagnum has devised its own natural defense system against insect and fungus attack
by liberating hydrogen ions and creating an intolerable pH level in its immediate
environment.

Limitations exist in the cultivation of S. cristatum mainly because it is very
slow growing and requires glasshouse conditions. The annual growth rate of natural S. cristatum populations is estimated to be between 0.4-4.2 cm. For these
reasons some gardeners who like to see instant results may be disappointed. S. cristatum is a beautiful and fascinating plant and is well worth the
little extra patience it requires to grow.

Text by Sharon Brown (2002 Student Botanical Intern)

Name meaning:
Sphagnum cristatum

Sphagnum - from the word sphagnos, which goes back as
far as the 4th century when it was used as a prescribed medication.
The actual meaning of the word is thought to be 'astringent';

cristatum - from the Latin cristatus, meaning 'crested'
and refers to the boat-shaped branch leaves which are wide and concave.